123 VIRUS STRUCTURE AND MORPHOLOGY VIRUS: Virus is a sub microscopte infectious agent that replicates only inside the living cells of an organism (08) that Visuses are small, obligate intracellular paмайте requires living host for replication/multiplication 2. GENERAL CHARACTERISTICS:- Viruses contain only the one type of nucleic acid etther DNA OF RNA but never borh They are uneffected by antibacterial antibiotics. This is the main difference between vious and other microorganisme The medical importance of Viruses lies in their ability to cause a very large number of human diseases. Viruses lack the enzymes necessary for protein synthesis and nucleic acid synthesis and are dependent for replication on the synthetic machinery of host cell. →Viruses may be sporadic, endemic, epidemic & pandemic Sporadic occurs only in fow places cors at foregular intervale £9:- Mumps Endemic Diseases regularly found among particular people | certain place couregion. By: Hepatitis Epidemic - wide spread occurence of an disease infection in a community at particulas time £9:- Influenza, Dengue fever pandemic - Disease, infection that spreads torsoccurs while Country (o) world wide L9: Corona 3. MORPHOLOGY:- Morphology is the Study of Size, shape, Structure and Symmetry of Visua Size - Vievers are smaller than bacteria, because of their Small size and filter ability [They can pass through a biological fitter] →viruses are too small to be seen under the light micaastape and can only seen under the election microscope. → so, visvies can be seen and measured by vôing • Elrofron microscope • vidza centrifugation • vera filteration →Visuses vary widely in size. →The biggest virus is poxvirus [300nm) and Smallest visus is parvovirus [isam] List of Some Viavase based on size: ►pex virus- - 300 min para myxovirus - 150mm ►Ortho myxo vidus- 180nm ►Bacteriophages-850m Retro Vinos 100mm ► Adeno visus -7200 ►Toga virus 700m form ►Tobacco mosaic - 18mm ►parvo visus 15m